The vagina is fairly resistant to infection due to its marked acidity, balanced ecosystem and thick protective epithelium. However, numerous insults can affect the vaginal defense system and lead to increased susceptibility to vaginal infection. For example, low estrogen levels in menopausal and hypogonadal women can affect the thickness of the vaginal epithelium. Antibiotics can alter the microbiology of the vagina. Semen during intercourse and blood during menstruation can increase vaginal pH. Stress, fatigue, chronic diseases such as diabetics and human immunodeficiency disease (HIV) affect not only the immune system but also the pH of the vagina. These factors can breakdown the balanced microenviroment in the vagina and increase the risk of vaginal infection by a variety of organisms.
Vaginal colonization of the vagina by pathogenic bacteria such as Escherichia coli is a significant step in ascending urinary tract infections (UTIs), which affect about 10–20% of women at some time in their life and which cost $5 billion per year in healthcare costs. Estrogen-depleted post-menopausal women are the highest risk group for acquiring urinary tract infections due to the thinning of the vaginal mucosa and the increased pH of the vaginal environment in these women. Recurrences of both vaginal and urinary tract infections are frequent following the initial episode. Hence, prevention of the initial infection is important for avoiding repeated urogenital infections.
Without treatment, vaginal infections can increase the risk of sexually transmitted diseases and induce complications such as urinary tract infections, pelvic inflammatory diseases and pre-term births. Currently, the control of such infections relies heavily on using antibiotics. However, extensive use of antibiotics for prevention of infection can be detrimental, not only because of the increased risk of generating antibiotic-resistant microorganisms, but also because indiscriminate killing of beneficial bacteria in urogenital tract can leave it susceptible to infection by other pathogens. Hence, there is increasing concern that compositions containing antibiotics should not be used routinely for treating urogenital infections.
Thus, a need exists for compositions and methods for preventing urogenital infections without the use of antibiotics or harsh chemicals that can upset the natural balance within the urogenital tract.